Bridge — box instead of Vorfinanzierung?

New flat closes before the old one settles. Three ways to bridge: bank Vorfinanzierung, box spread, or sell investments.

Tune assumptions
7.00%
40%
6.5%
Box rate pulled live from the EUR curve at the exact tenor. With offset on, the box loss reduces tax owed on other Kapitalerträge in the same year.
Box saves vs. bank · €10,779
Box rate (6m EUR) · 2.34%
Offset on — box cost net of −€1,228 tax refund
A · Bank Vorfin 7.00%
€14,206
B · Box spread 2.34%
€3,427
C · Sell investments
€48,686
Tax leak
€47,177
Gross sold
€447,177
Foregone return
€1,509

How the comparison works

A · Bank Vorfin

Short-term bridge facility from the house bank. Fast, but expensive — retail rates typically sit at 6–9% p.a. even for short tenors.

B · Box spread

Short box on EUREX with tenor matching the bridge. Collateralised by the portfolio, rate typically near ESTER + 30–80bp.

C · Sell investments

Sell enough ETF to cover the bridge — Abgeltungsteuer on the realised gain portion. With a large unrealised pile this gets expensive fast.